It was discovered that CVE-2011-3004, which addressed possible privilege
escalation in addons, also affected Firefox 3.6. An attacker could
potentially exploit Firefox when an add-on was installed that used
loadSubscript in vulnerable ways. (CVE-2011-3647)

Yosuke Hasegawa discovered that the Mozilla browser engine mishandled
invalid sequences in the Shift-JIS encoding. A malicious website could
possibly use this flaw this to steal data or inject malicious scripts into
web content. (CVE-2011-3648)

Marc Schoenefeld discovered that using Firebug to profile a JavaScript file
with many functions would cause Firefox to crash. An attacker might be able
to exploit this without using the debugging APIs which would potentially
allow an attacker to remotely crash the browser. (CVE-2011-3650)

Update instructions:

The problem can be corrected by updating your system to the following
package versions: